Kang RA, et al. - In this study including patients scheduled for arthroscopic shoulder surgery, researchers investigated the clinically relevant dose of intravenous (IV) dexmedetomidine (DEX) to prolong the analgesic duration of interscalene brachial plexus block (ISBPB). ISBPB with 15 mL of 0.5% ropivacaine with 1:200,000 epinephrine was administered to patients; followed by random assignment to 1 of 4 groups: IV normal saline (control), IV DEX 0.5 μg/kg (DEX 0.5), IV DEX 1.0 μg/kg (DEX 1.0), and IV DEX 2.0 μg/kg (DEX 2.0). The focus was on time to the first pain at surgical site. They found that in patients who received intravenous DEX at a dose of 2.0 μg/kg, the duration of ISBPB analgesia was significantly increased with no prolonged motor blockade and the cumulative opioid consumption at the first 24 hours was attenuated.